The Gene Therapy Working Group and Biostatistics Core provides the services necessary for the development, administration and evaluation of gene therapy clinical trials. This core is a unique multi-disciplinary group that brings together the principal participants of gene therapy clinical trials in an ongoing weekly meeting. The Gene Therapy Working Group and Biostatistics Core has been the focal point for coordination of preclinical development, protocol inception, regulatory approval, protocol execution, and data retrieval and analysis. The use of this core is expected to increase over the next few years as patient trials are pursued. This core provides direction for preclinical basic science investigations to generate the information necessary to rationally design gene therapy clinical trials. This has resulted in a collaborative effort in construction of retroviral vectors and in defining preclinical and clinical parameters for stem cell manipulation. The specific service component of the Gene Therapy Working Group and Biostatistics Core is coordination of protocol development, regulation approval, interfacing clinical care with research components of the trial, and management of clinical data. These services are implement by the Gene Therapy Clinical Research Coordinator and Gene Therapy Research Nurse. The Gene Therapy Working Group and Biostatistics Core provides the organization and coordination required for these complex initiatives which demand the interaction of individuals with a wide range of expertise performing distinct roles. The core provides an environment for ongoing analysis and quality control of clinical trials. The integration of these practical components represents the cornerstone for efficient, successful development and execution of clinical gene therapy protocols.